1. Field of the Invention
The present invention relates to an air conditioner outlet vent device that is mounted in an instrument panel of an automobile, etc. and, in particular, to an improvement in an air conditioner outlet vent device in which either one of a blade or a housing that surrounds the blade is molded as a primary molding having a shaft hole by primary injection using a first synthetic resin, the other one of the blade or the housing is molded within a secondary mold die, in which the primary molding has been set, as a secondary molding having a support shaft corresponding to the above-mentioned shaft hole by secondary injection using a second synthetic resin so that the shaft hole and the support shaft are fitted together at the same time as they are molded, and being so fitted together the blade can pivot within the housing.
2. Description of the Related Art
Such an air conditioner outlet vent device is already known as disclosed in, for example, Japanese Patent Application Laid-open No. 10-82554, in which a housing with shaft holes is formed by primary molding and blades with support shafts are formed by secondary molding.
In this conventional device, with regard to the materials forming the housing and the blade, in order to avoid melt-bonding between the housing and the blade during secondary molding, they are made from different synthetic resin materials that are chosen so that the secondary injection material has a melting point lower than that of the primary injection material (for example, an ABS resin for the housing and a polypropylene resin for the blade).
Furthermore, in this conventional device, taking into consideration the thermal deformation of the blade, in order to prevent the blade from dropping out due to its shrinkage, an surplus shaft section which protrudes from the housing is provided on the support shaft of the blade.
However, as in the above-mentioned conventional device, when materials of different systems are used for the housing and the blade, a step of separating the housing and the blade is required for recycling. Taking into consideration the cost and labor of this step, it is difficult to recycle the material in practice.
If, taking recycling into consideration, materials of the same system are used for the housing and the blade, the percentage mold shrinkage of the shaft hole and that of the support shaft become approximately equal, and there are the problems that the support shaft comes into close contact with the shaft hole thus melt-bonding the two and it is difficult to adjust the feeling given by pivoting of the blade.
In particular, in the structure in which an surplus shaft section is provided on the blade support shaft in order to prevent the blade from dropping out due to its shrinkage, the surplus shaft section protrudes from the housing. In particular, in an outlet vent device of a type in which the air is directed by pivoting the housing itself relative to a fixed support, there are the problems that the surplus shaft section might obstruct the pivoting of the housing and degrade the appearance by being exposed to the passenger compartment when pivoting the housing.
The present invention has been carried out in view of the above-mentioned circumstances, and it is a main object of the present invention to provide an air conditioner outlet vent device in which even when, taking recycling into consideration, a housing and a blade are made from materials of the same system, the percentage mold shrinkage of the shaft hole can be made smaller than that of the support shaft by a simple arrangement so as to avoid melt-bonding between the shaft hole and the support shaft, and the feeling given by pivoting of the blade can easily be adjusted.
In order to achieve the above-mentioned object, in accordance with a first aspect of the present invention, there is proposed an air conditioner outlet vent device in which one of a blade and a housing that surrounds the blade is molded as a primary molding having a shaft hole by primary injection using a first synthetic resin, the other of the blade and the housing is molded, within a secondary mold die where the primary molding has been set, as a secondary molding having a support shaft corresponding to the shaft hole by secondary injection using a second synthetic resin so that the shaft hole and the support shaft are fitted together at the same time as they are molded, thereby enabling the blade to pivot within the housing, wherein: the first and second synthetic resins are of the same synthetic resin system, and an additive for suppressing shrinkage of the primary molding in cooling and solidifying it after injection molding is added to the first synthetic resin so that the percentage mold shrinkage of the shaft hole becomes smaller than that of the support shaft. In accordance with the above-mentioned proposed arrangement, even when, taking recycling into consideration, the housing and the blade are made from materials of the same system, the percentage mold shrinkage of the shaft hole can be made smaller than that of the support shaft by the simple arrangement of merely adding the above-mentioned additive to the first synthetic resin used for the primary injection. Therefore, it is possible to effectively prevent melt-bonding between the shaft hole and the support shaft and, moreover, by merely controlling the amount of the above-mentioned additive, the feeling given by pivoting of the blade can easily be adjusted.
Furthermore, in accordance with a second aspect of the present invention, there is proposed an air conditioner outlet vent device in which one of a blade and a housing that surrounds the blade is molded as a primary molding having a shaft hole by primary injection using a first synthetic resin, the other of the blade and the housing is molded, within a secondary mold die where the primary molding has been set, as a secondary molding having a support shaft corresponding to the shaft hole by secondary injection using a second synthetic resin so that the shaft hole and the support shaft are fitted together at the same time as they are molded, thereby enabling the blade to pivot within the housing, wherein: the first and second synthetic resins are of the same synthetic resin system, an additive for suppressing shrinkage of the primary and secondary moldings in cooling and solidifying them after injection molding is added to each of the first and second synthetic resins at different ratios of the amounts of the additive added to the two synthetic resins so that the percentage mold shrinkage of the shaft hole becomes smaller than that of the support shaft. In accordance with the above-mentioned proposed arrangement, even when, taking recycling into consideration, the housing and the blade are made from materials of the same system, the percentage mold shrinkage of the shaft hole can be made smaller than that of the support shaft by a simple arrangement of merely changing the ratio of the amounts of additive added to the first synthetic resin used for the primary injection and the second synthetic resin used for the secondary injection. Therefore, it is possible to effectively prevent melt-bonding between the shaft hole and the support shaft. Moreover, since the percentage mold shrinkage of the shaft hole and the support shaft can be changed individually by adding the additive to the two synthetic resins, the feeling given by pivoting of the blade can yet more easily be adjusted.
Furthermore, in accordance with a third aspect of the present invention, in addition to the second aspect, there is proposed an air conditioner outlet vent device wherein the primary molding is the housing, the secondary molding is the blade, and the support shaft formed on the blade does not protrude from the housing. In accordance with the above-mentioned proposed arrangement, the appearance of the device is improved and its size is decreased. Therefore, even when this arrangement is applied to an outlet vent device of, for example, the type in which air is directed by pivoting the housing itself relative to a fixed support frame, there is no possibility that the support shaft might interfere with the pivoting of the housing or the support shaft might be exposed to a passenger compartment when pivoting the housing, thus degrading its appearance. Moreover, since the mold shrinkage of the blade can be controlled to an appropriate level by adding the above-mentioned additive to the blade, it is possible to effectively prevent the support shaft from dropping out of the shaft hole without making the support shaft protrude from the housing.
Furthermore, in accordance with a fourth aspect of the present invention, in addition to the above-mentioned first, second or third aspect, there is proposed an air conditioner outlet vent device wherein one of the first and second synthetic resins is polyethylene and the other is polypropylene. In accordance with the above-mentioned proposed arrangement, when selecting materials for the housing and the blade, since a combination of polyethylene and polypropylene which are general as recycling materials, can be employed, recycling becomes extremely easy.
Furthermore, in accordance with a fifth aspect of the present invention, in addition to the above-mentioned first, second or third aspect, there is proposed an air conditioner outlet vent device wherein the above-mentioned additive has a function of enhancing the heat resistance of the molding. In accordance with a sixth aspect of the present invention, in addition to the above-mentioned fourth aspect, there is proposed an air conditioner outlet vent device wherein the above-mentioned additive has a function of enhancing the heat resistance of the molding. In accordance with the above-mentioned proposed arrangements, since the heat resistance of the molding to which the additive is added is enhanced, a comparatively inexpensive synthetic resin material having low heat resistance can be chosen as a material for the molding, thus reducing the unit cost of the product. For example, when the molding is a blade that is required to have heat resistance, a comparatively inexpensive synthetic resin material having low heat resistance can be chosen as a blade material, thus reducing the unit cost of the blade.
The xe2x80x98percentage mold shrinkagexe2x80x99 referred to in the present invention denotes the percentage of the change due to actual shrinkage of the molding based on reference dimensions obtained on the assumption that the molding did not shrink at all on cooling and solidifying after injection molding. The smaller the percentage mold shrinkage, the smaller the degree of shrinkage, that is to say, it is described as being difficult to shrink.
The above-mentioned objects, other objects, characteristics and advantages of the present invention will become apparent from explanations of preferred embodiments that will be described in detail below by reference to the attached drawings.